Affinity capillary electrophoresis (ACE) will be applied to surface- surface recognition events between liposomes hearing arylsulfonamide or sialic acid ligands and their target proteins carbonic anhydrase (CA) and bromelain cleaved hemagglutinin (BHA) present in their native biologically active forms. The first goal is to demonstrate the broad applicability of ACE as an analytical tool in biochemistry by application to mesoscopic particles. These studies could form the basis for examination of cells by ACE. The second goal of this project is to gain an improved understanding of the differences between interactions at the surface-surface and surface-solution interface as well as the differences between monovalent and polyvalent interactions. Since many biological processes, for example infection of cells by the influenza virus, occur by the recognition of a receptor present on the cell surface, the knowledge gained will be biologically relevant. Liposomes are selected as a model system since liposomes possessing relevant and varied surface functionality are easily prepared and purified. Equilibrium and kinetic binding constants will be determined by ACE based on the change in electrophoretic mobility of the liposome on binding the smaller charged proteins. Studies of the monovalent (CA) and trivalent (BHA) interaction while selectively altering the surface characteristics of the liposome should provide significant insight into surface-surface binding events.